1. Technical Field
The present invention is directed toward weir gates, and more particularly toward adjustable weir gate assemblies for independently regulating the flow of a fluid medium at discrete points along a fluid conveying trough.
Weirs for controlling a flow are old in the art, and generally involve placing a dam across a river or canal to raise or divert the water, as for the fast-moving stream of water that drives a mill wheel or to regulate the flow. These structures typically comprise a fence or wall or similar structure which is immersed within the flow.
2. Background Art
In the preparation of certain bulk pulverant materials, it is often desirable to convey a volume of the materials between a number of locations while the material is being treated. To this end, conveyors having an elongated trough with vibration generation means for producing forces to advance the material between the remote locations have been developed by the assignee of the Applicant, as in U.S. Pat. Nos. 3,089,861; 3,898,227; and the like. Together with moving the material along the trough by use of vibration generating means, certain pulverant materials are fluidized by forcing air or other gases upward through the material, creating a moving fluidized bed of material. Where the fluidized material requires various forms of working prior to delivery to a remote location, assorted fluid working implements are positioned along the trough at discrete fluid working zones or stations. As the fluidized bed of material moves along the trough it passes through a work station, at which point the appropriate work is performed thereon.
The preparation and treatment of high volumes of fluidized materials requires the continuous operation of a fluid conveyor to achieve a profitable production efficiency. As a result, the rate at which the material is conveyed along the trough establishes the amount of time at which a particular element of fluidized material is subjected to working at a particular station. A critical deficiency arises, therefore, in situations in which it is required to work the fluidized material for different amounts of time at the various work stations. Because the material travels along a common conveyor, the material travels through each work station at the same rate. While the conveyance rate may allow for adequate working of the fluidized material at some stations, for working steps which require an increased amount or a decreased amount of working time, the fluidized bed of material is improperly worked.
This represents a significant problem. If the rate of conveyance is reduced to increase the amount of time at which the material is worked at otherwise insufficiently worked stations, the otherwise properly worked material will thus be overworked. An analogous situation results if the rate of conveyance is increased. While the amount of time at which the fluidized bed of material is worked at an otherwise overworked station is reduced, the otherwise properly worked material will thus be under worked.
The present invention is directed to overcoming the problems discussed above.